Methods and Devices to Reduce the Likelihood of Injury from Concussive or Blast Forces

ABSTRACT

A method and device for reducing the damaging effects of radiant energy, blast, or concussive events includes applying pressure to at least one jugular vein to reduce the egress of blood from the cranial cavity during or before the incidence of the imparting event. Reducing blood outflow from the cranial cavity increases intracranial volume and/or pressure of the cerebrospinal fluid to reduce the risk of traumatic brain injury and injuries to the spinal column. Reducing blood outflow further increases the intracranial pressure and volume, and thereby increases the pressure and volume of the cochlear fluid, the vitreous humor and the cerebrospinal fluid to thereby reduce the risk of injury to the inner ear, internal structure of the eye and of the spinal column. In addition, increasing intracranial pressure and volume reduces the likelihood of brain injury and any associated loss of olfactory function

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. application Ser. No.13/841,195, filed Mar. 15, 2013, which is incorporated herein in itsentirety.

TECHNICAL FIELD

The present disclosure is generally related to methods and devices forreducing the effects of exposure to concussive events.

BACKGROUND OF THE INVENTION

Traumatic brain injury (TBI) continues to be one of the most commoncauses of death and morbidity in persons under age 45, even in westernsocieties. A reported 1.7 million people suffer from TBI annually in theUnited States alone, resulting in an estimated per annum total cost ofover $60 billion. Historically, prevention of skull and brain injury hasfocused on the use of helmets as external cranial protection. Thisapproach is fundamentally flawed as helmets have provided benefit foronly major penetrating brain injuries and skull fractures. These occurin a very small fraction of head injuries in civilian sphere. Militarystatistics have shown that even on the battlefield, less than 0.5% ofTBI is from a penetrating object. However, both military personnel andathletes are subjected to high velocity acceleration-decelerationmechanisms that are not mitigated by helmets and lead to concussiveinjury to the brain. In large part, the human brain's relative freedomof movement within the cranial cavity predisposes to both linear androtational force vectors, with resultant energy absorption resulting incellular disruption and dysfunction, sometimes with delayed cell death.

The skull and spinal canal contain only nervous tissue, connectivetissue and fat cells and their interstitium, blood, and cerebrospinalfluid (CSF). The non-fluid contents do not completely fill the rigidcontainer delimited by the skull and bony spinal canal, leaving a‘reserve volume’ that is occupied by the fluid components. The change involume inside a container for a given change in pressure is termed‘compliance’. Increases in volume of the contents of the skull and bonyspinal canal, within the range of reserve volume, occur at low containerpressures (due to the high compliance of the system). Acceleration ordeceleration of the skull can result in a differential acceleration ordeceleration between the skull and its contents when the brain andfluids collide with the inside of the skull. TBI may occur because ofcompression, stretching, or tearing of tissue and blood vessels as aresult of the brain impacting the skull. Considering the semi-solidproperties of the mammalian brain, this effect is referred to as“SLOSH”.

While helmets are effective in preventing the infrequent penetration orfracture of the skull, they have little ability to limit SLOSH effects.Mitigating SLOSH by increasing the pressure of the fluid contents of thebrain can significantly reduce the propensity for damage to the braintissue or its blood vessels by reducing the compressibility of thebrain. The reduction in compressibility results in reduced absorption ofkinetic, acoustic, thermal, and vibrational energy by the brain.

The same concussive events that produce TBI can also have damagingeffects to the inner ear, spinal cord and structures of the eye. Sensoryneural hearing loss is noted to occur at a rate of 85% in TBI.Concurrent injuries to the auditory system as a result of acute blasttrauma and resultant traumatic brain injury accounted for one-quarter ofall injuries among marines during Operation Iraqi Freedom through2004—the most common single injury type. Auditory dysfunction has becomethe most prevalent individual military service-connected disability,with compensation totaling more than $1 billion annually.

Although one might expect blast waves to cause tympanic membrane ruptureand ossicular disruption (thus resulting in conductive hearing loss),available audiology reports showed that pure sensory neural loss was themost prevalent type of hearing loss in patients. An observational studyperformed from 1999-2006 found that 58 percent of active-duty soldierswho complained of hearing loss were diagnosed with pure sensorineuralloss. Data from this study revealed that 38 percent of the patients withblast related TBI also reported sensory neural tinnitus (ringing in theears).

The sites for sensory neural hearing loss are the inner ear structuresreferred to as the cochlea and vestibular apparatus (semicircularcanals). Both of these structures are fluid filled and thereforesusceptible to SLOSH induced energy absorption. The tympanic andvestibular canals of the cochlea are also fluid filled and transmitpressure and fluid waves to the delicate hair cells of the organ ofcorti. The auditory hair cells react directly to the vibrations in theliquid in which they are immersed rather than to transverse vibrationsin the cochlear duct. The cochlea and its associated hair cells areparticularly susceptible to SLOSH energy absorption.

Approximately 30 ml (21%) of a total CSF volume of 140 ml resides withinthe spinal axis, and about one-third of the compliance of the CSF systemhas been attributed to the spinal compartment. As in the brain,increasing the pressure of the CSF within the spinal compartment reducesthe susceptibility of the spinal compartment to concussive injuries byincreasing the elasticity of the contents of the spinal column, therebyreducing the amount of energy absorbed by the contents of the spinalcolumn when subjected to a concussive force.

Of 207 severe eye injuries in a report of military casualties inOperation Iraq Freedom OIF, 82 percent were caused by blast and blastfragmentation. Eye injuries accounted for 13 percent (19/149) of allbattlefield injuries seen at a combat support hospital during OperationsDesert Shield and Desert Storm. Hyphema (blood within the anteriorchamber) and traumatic cataract were the most common findings in closedglobe injuries, the majority (67%) of eyes sustained orbital injury. Ofthe service members experiencing combat ocular trauma (COT) in OperationEnduring Freedom, 66 percent also had TBI. Simply stated, roughlytwo-thirds of the combat related eye injuries were closed blast waveenergy absorptions resulting in rupture.

Traumatic brain injury, or the concussive or blast-related eventsleading to TBI, has also been found to be a leading cause of anosmia(loss or impairment of olfactory function, i.e., sense of smell).Certain studies have reported that a large proportion of patients withpost-traumatic anosmia exhibit abnormalities in the olfactory bulbs andin the inferior frontal lobes, suggesting in the latter case thatreducing TBI can reduce the risk of anosmia. While loss or impairment ofolfactory function can be more than a nuisance to humans, the sameinjury to Breecher dogs (e.g., bomb sniffers) can be catastrophic.Breecher dogs are inherently exposed to the risk of concussive eventsand their primary purpose is to help soldiers avoid such an event.Preventing or reducing the likelihood of TBI and associated loss ofsmell can be critical to the Breecher dog's mission.

Standard prophylactic measures designed to protect the brain againstinjury in the case of head trauma have hitherto included only varioushelmets. Helmets are primarily designed to protect the skull frompenetrating injuries and fractures, but less so from pathologicalmovements of the brain, exemplified by the classic cerebral concussion.Moreover, helmets have no meaningful effect on blast-related injuries tothe ear, spinal column and eyes.

SUMMARY OF THE INVENTION

Intracranial injuries due to exposure to external concussive forcesremains a devastating condition for which traditionally extra-cranialprotection has been utilized in the form of helmets. Although headgearis effective in preventing the most devastating intracranial injuries,penetrating injuries, and skull fractures, it is limited in its abilityto prevent concussions or damage to the structures within the cranium.In accordance with one disclosed method, the internal jugular vein (IJV)is mildly compressed to increase cerebral blood volume and decrease theintracranial compliance. This results in increased intercranial volumeand resultant pressure and thus reduction of the differentialacceleration between the skull and its contents when subjected to aconcussive force. Reduction in the differential acceleration between theskull and its contents means a reduction in propensity for compression,stretching, or tearing of the brain or vascular tissues within theskull, leading to less energy absorption, and thus less traumatic axonaland glial injury. Mild restriction of flow of the IJV also leads toincreased cochlear pressure to reduce risk of damage to the inner ear,increased pressure in the cerebrospinal fluid to reduce the risk ofinjury to the spinal column, and increased intraocular pressure toprotect the internal structure of the eye from concussive events.

In an attempt to mitigate intracranial slosh it is recognized that thesingle intracranial compartment that is most amenable to rapid,reversible change in volume and pressure is the blood space. Thesimplest and most rapid means of increasing the volume blood compartmentis to inhibit its outflow by mechanically restricting one or more of thedraining veins in the neck.

One aspect of the disclosure, therefore, encompasses methods forreducing the likelihood of injury to a subject exposed to externalconcussive force, comprising: contacting one or more protuberances tothe neck of the subject, wherein each protuberance is located above oneor more neck veins of the subject; and applying an external pressure tothe protuberances sufficient to restrict blood flow egressing from thehead of the subject through the one or more neck veins. In someembodiment, the injury comprises one or more selected from the groupconsisting of traumatic brain injury, concussive injury to the spinalcolumn, concussive injury to the inner ear, and concussive injury to theocular or olfactory structures.

In some embodiments, the one or more veins in the neck of the subjectcomprises one or more of an interior or exterior jugular vein. In somerelated embodiments, restriction of the blood flow egressing from thehead of the subject results in an increase in fluid volume and pressurein the intracranial cavity of the subject. The cranial volume is notfixed as the eyeballs and the tympanic membranes can slightly bulgeoutward (as in the jugular tympanic reflex), further the foramen oropening of the cranial vault are all able to accommodate a greatervolume. In some embodiments, the external pressure applied to the one ormore veins in the neck is equivalent to a fluid pressure of 5-25 mm Hg.

Other aspects of this disclosure encompass devices that reduce the riskof traumatic brain injury from concussive events in an animal or humansubject by reducing the flow of one or more neck veins by compressing atleast one of said veins. The devices of this aspect comprise at leastone region (i.e., a protuberance) that is inwardly directed and contactsthe neck of the wearer of the device, thereby applying a localizedpressure to a neck vein.

In some embodiments, the device comprises a circumferential collar sizedto encircle the neck of a subject; and one or more inwardly directedprotuberances integral to the collar; wherein the protuberances arelocated on the collar such that they are disposed above one or more neckveins of the subject when the collar is encircling the neck of thesubject; and wherein the collar is sized so as to exert sufficientpressure on the protuberances to restrict blood flow egressing from thehead of the subject through the one or more neck veins.

In some related embodiments, the circumferential collar is sized to bepositioned between the collar bone and the cricoids cartilage of thesubject.

In some related embodiments, the collar defines a cut-out sized andpositioned to provide clearance for the laryngeal prominence when thecollar encircles the neck of the subject.

In some related embodiments, at least a portion of the circumferentialcollar comprises an elastic material capable of stretching so as toincrease the circumference of the collar. In some further relatedembodiments, the collar further comprises a compression indicatorassociated with said elastic material configured to provide a visualindication of the elongation of said portion when encircling the neck ofthe subject.

In some related embodiments, the circumferential collar comprises arigid or semi-rigid portion defining a bridge spanning the laryngealprominence.

In some related embodiments, the circumferential collar comprises aflexible material strap and engagement elements at opposite ends of saidstrap configured to be releasably engaged so as to encircle the neck ofthe subject. In some further related embodiments, the collar furthercomprises a rigid or semi-rigid portion defining a bridge spanning thelaryngeal prominence, wherein the engagement elements at opposite endsof the strap are configured to be releasably engaged to correspondingends of the rigid or semi-rigid laryngeal bridge. In some furtherrelated embodiments, the flexible material strap comprises an elasticmaterial capable of being stretched so as to increase the circumferenceof the collar.

In some related embodiments, the circumferential collar furthercomprises one or more bladders disposed within the circumferentialcollar. In some further related embodiments, at least one of thebladders is disposed within the circumferential collar at a locationother than above the protuberances. In some further related embodiments,at least one of the bladders is disposed at a location above one or moreof the protuberances. In some further related embodiments, aprotuberance is defined by the one or more bladders. In some furtherrelated embodiments, at least one of the bladders contains a reversiblycompressible foam material, and wherein the interior of thefoam-containing bladder is in fluid communication with the exterior ofthe bladder via a pressure relief valve. In some further relatedembodiments, the circumferential collar further comprises a pump elementin fluid communication with a bladder, whereby the fill level of abladder can be adjusted.

In some related embodiments, the circumferential collar furthercomprises a cable-tie ratcheting fit adjustment system, comprising oneor more cable-tie type ratcheting tabs; and one or more receivers forsaid tabs, wherein each of the cable-tie type ratcheting tabs isdisposed so as to pass through a receiver. The receivers are configuredto allow movement of a ratcheting tab through the receiver in onedirection thereby reducing the circumference of the circumferentialcollar, but prevent movement of the ratcheting tab in the reversedirection. Additionally, the ratcheting tabs are configured to breakaway from the circumferential collar at a point below theircorresponding receivers when pulled away from the circumferential collarat a force greater than or equal to a predetermined level.

In some related embodiments, the circumferential collar furthercomprises a cable ratcheting fit adjustment system, comprising: one ormore cables spanning at least a portion of the circumference of thecollar; and one or more ratcheting elements, with each ratchetingelement attached to at least one of the cables. In these embodiments,each of the ratcheting elements is configured to adjust thecircumference of the collar by adjusting the length of a cable spanningat least a portion of the circumference of the collar. In some furtherrelated embodiments, the ratcheting fit adjustment system furthercomprises an adjustment tool distinct from the circumferential collar,configured to reversibly engage with the ratcheting system. In somealternative embodiments, the ratcheting fit adjustment system furthercomprises an adjustment tool integral to the circumferential collar.

In some related embodiments, the device further comprises one or morediscernible graphic or tactile reference points on an exterior surfaceof the device.

In some related embodiments, the circumferential collar furthercomprises one or more sensors capable of detecting pulse, bloodpressure, or other indicia of proper placement and pressure of aprotuberance above a neck vein. In some further related embodiments, thedevice further comprises a transmitter operably connected to a sensor,wherein the transmitter is capable of transmitting a signal indicativeof a sensor reading to an external device. In some further relatedembodiments, the device further comprises an electronic circuit operablyconnected to a sensor, whereby the electronic circuit is configured toprovide visual or auditory indicia of proper fit and/or alignment. Insome embodiments, visual indicia may comprise light from a lightemitting diode (LED). In some embodiments, auditory indicia may comprisesound from a speaker.

In some embodiments, the device comprises a semi-circumferential collarcomprising a resilient arcuate band having a general C, V, or U-shapeand sized to encircle a majority of the neck of a subject; and one ormore inwardly directed protuberances integral to thesemi-circumferential collar. In these embodiments, the protuberances arelocated on the semi-circumferential collar such that they are disposedabove one or more neck veins of the subject when the collar isencircling a portion of the neck of the subject; and the collar is sizedso as to exert sufficient pressure on the protuberances to restrictblood flow egressing from the head of the subject through the one ormore neck veins.

In some related embodiments, the semi-circumferential collar is sized tobe positioned between the collar bone and the cricoids cartilage of thesubject.

In some related embodiments, the semi-circumferential collar has anopening at the front of the neck or at the back of the neck.

In some embodiments, the device comprises: a flexible material sized toencircle a minority of the circumference of the neck of a subject; andone or more inwardly directed protuberances contacting an inner surfaceof said flexible material. In these embodiments, the flexible materialis sized such that an inner surface of the flexible material extendsbeyond a protuberance, and the protuberances are of appropriate size andshape such that when placed on the neck above a neck vein of thesubject, the device restricts blood flow egressing from the head of thesubject.

In some related embodiments, the flexible material comprises a plasticor woven fabric.

In some related embodiments, a portion of the flexible material thatextends beyond a protuberance is coated with an adhesive.

In some related embodiments, the flexible material is an elasticmaterial. Alternatively, in some related embodiments, the flexiblematerial is an inelastic material.

In some related embodiments, a protuberance is defined by an outwardbend point of a resilient arcuate band having a general C, V, orU-shape.

In some related embodiments, the devices are intended to be applied tothe neck of a subject in pairs. In some related embodiments, two of suchdevices are attached to each other by a removable tether; wherein theremovable tether is sized to facilitate appropriate spacing andalignment during application to the neck of a subject.

In some embodiments, the device comprises a resilient arcuate bandhaving a general C, V, or U-shape and sized to encircle a minority ofthe neck of a subject, and one or more inwardly directed protuberances.In these embodiments, when applied to the neck of a subject, theresilient arcuate band is configured to apply pressure to one or moreprotuberances to restrict blood flow egressing from the head of thesubject.

Yet other aspect discloses garments comprising: a collar sized to atleast partially encircle the neck of a subject; and one or more inwardlydirected protuberances integral to the collar. In such garments, thewherein the protuberances are located on the collar such that they aredisposed above one or more neck veins of the subject when the garment isworn; and wherein the garment provides sufficient pressure on theprotuberances to restrict blood flow egressing from the head of thesubject through the one or more neck veins.

As used herein, the term “circumferential collar” is used to describe adevice which encircles the entire circumference of the neck when thedevice is worn by an animal or human subject. As used herein, the term“semi-circumferential collar” is used to describe a device whichencircles a majority of the circumference of the neck when the device isworn by an animal or human subject. The portion of the circumference ofthe neck that is not encircled by a semi-circumferential collar may bedisposed at any location around the circumference of the neck, so longas the encircled portion allows for application of pressure on a neckvein of the wearer. Typically, the open portion will be located eitherat the front of the throat (e.g., in some embodiments, asemi-circumferential collar may encircle the neck except an areasubstantially defined by laryngeal prominence), or the open portion willbe located at the back of the neck. Additional details are describedbelow.

In some embodiments, the collar may comprise a textile. In relatedembodiments, the collar may comprise an elastic material.

In some embodiments, the circumferential or semi-circumferential collarmay comprise a semi-rigid shape-memory material, such as a suitablepolymer (e.g., an elastomer) or shape-memory alloy.

In some embodiments of this aspect of the disclosure, the collar sizeand tension thereof can be adjustable. In some embodiments of thisaspect of the disclosure, the device can further comprise one or morebreakaway release mechanisms.

In some embodiments of this aspect of the disclosure, at least oneregion of the device inwardly directed to contact the neck of a subjectcan be formed by inflation of a region of the collar, and wherein thedevice optionally further comprises a pump to inflate the inflatableprotuberance, or any region of said device, and optionally a source ofpressurized gas or fluid for inflation thereof. In some embodiments ofthis aspect of the disclosure, the device can further comprise a releasevalve to regulate the pressure in said collar.

Another aspect of the disclosure encompasses embodiments of a method ofincreasing the intracranial volume and pressure of an animal or humansubject comprising:

-   (i) encircling the neck of an animal or human subject with a collar,    wherein said collar has at least one region inwardly directed to    contact the neck of an animal or human subject;-   (ii) positioning the at least one region inwardly directed to    contact the neck on a region of the neck overlying a neck vein    carrying blood from the intracranial cavity of the subject; and-   (iii) applying pressure to the neck vein by pressing the at least    one region inwardly directed to contact the neck onto the surface of    the neck, thereby restricting blood flow egressing the intracranial    cavity of the subject, thereby increasing the intracranial pressure    and or volume of the subject.

Further aspects of the present disclosure provides methods formitigating injury to the inner ear, ocular structure and the spinalcolumn, and for preventing loss of olfactory function. In the method formitigating injury to the inner ear, pressure is applied to the jugularveins to thereby increase cochlear fluid volume and pressure during theconcussive event. In the method for mitigating injury to the ocularstructure, pressure is applied to the jugular veins to thereby increaseintraocular fluid pressure during the concussive event. In the methodfor mitigating injury to the inner ear, pressure is applied to thejugular veins to thereby increase cerebrospinal fluid volume andpressure during the concussive event. Applying pressure to the jugularveins also reduces or prevents loss of olfactory sense due to increasedintracranial volume and pressure.

BRIEF DESCRIPTION OF THE DRAWINGS

Further aspects of the present disclosure will be more readilyappreciated upon review of the detailed description of its variousembodiments, described below, when taken in conjunction with theaccompanying drawings.

FIGS. 1( a)-1(c) are top and side views of a compression collaraccording to one disclosed embodiment.

FIG. 2 is a top view of a compression collar according to a furtherdisclosed embodiment.

FIG. 3 is a top view of compression collar according to anotherdisclosed embodiment.

FIG. 4 is a top view of a compression collar of another embodimentincorporating a compression indicator.

FIG. 5 is a top view of an overlay to be mounted on the collar of FIG.4.

FIG. 6 is a top partial view of the compression collar and overlay ofFIGS. 4-5.

FIGS. 7( a)-7(c) are successive views of the overlay and indicatorstrips of the compression collar shown in different degrees of stretchof the collar.

FIG. 8 is a graph illustrating the change in intracranial pressure (ICP)as a consequence of IJV compression, p-value <0.01.

FIG. 9 is a graph illustrating the change in intraocular pressure (TOP)as a consequence of IJV compression, p-value 0.01.

FIG. 10 is a graph showing a representative tracing of physiologicchange seen in intracranial pressure (ICP) and intraocular pressure(IOP) over a fifteen minute period caused by the application (arrow onleft) and removal of IN compression (arrow on right). Of note is therapid response seen in both ICP and IOP and corresponding volumesfollowing IJV compression as well as the duration for which thesechanges are sustained.

FIG. 11A is a digital image of corticospinal tracts stained for APPpost-injury without application of the IJV compression device accordingto the disclosure.

FIG. 11B is a digital image of corticospinal tracts stained for APPpost-injury with application of the IJV compression device according tothe disclosure.

FIG. 12 is a graph illustrating the effect of IJV compression on axonalinjury as indicated by APP staining, p-value <001.

FIG. 13 shows an illustration of a circumferential collar made of anelastic material that may be used in various embodiments of the presentinvention.

FIG. 14 shows an illustration of one embodiment of the present inventioncomprising a circumferential collar, a fastener for opening and closing,and two protuberances configured to apply pressure to a neck vein of awearer.

FIG. 15 shows an illustration of one embodiment of the present inventioncomprising a circumferential collar, a fastener for opening and closing,a laryngeal bridge, and two protuberances configured to apply pressureto a neck vein of a wearer.

FIG. 16 shows an illustration of one embodiment of the present inventioncomprising a circumferential collar comprising two pieces: a first piece(i.e., front section) comprising and two protuberances each configuredto apply pressure to a neck vein of a wearer, and second piece (i.e.,back section) comprising a fabric collar configured to be removablyattached to either end to the first piece.

FIG. 17 shows an illustration of one embodiment of the present inventioncomprising a circumferential collar, a fastener for opening and closing,and two protuberances each (comprising a bladder and a pressure releasevalve) configured to apply pressure to a neck vein of a wearer.

FIG. 18 shows an illustration of a semi-circumferential collar with afront opening that may be used in various embodiments of the presentinvention.

FIG. 19 shows an illustration of a semi-circumferential collar with aback opening that may be used in various embodiments of the presentinvention.

FIGS. 20A-C show illustrations of exemplary embodiments of the presentinvention that apply pressure on appropriate positions on the neckwithout the use of a circumferential collar. These embodiments aretypically worn as pairs, with a device worn one either side of the neck.Optionally, the devices may further includes a removable tether of theappropriate length between a pair of devices that acts as an alignmentand spacing guide for application to the neck.

FIG. 21 is an illustration of another embodiment of the presentinvention that applies pressure on appropriate positions on the neckwithout the use of a circumferential collar. The device shown in FIG. 21is similar to those of FIGS. 20A-B, but further includes a removabletether of the appropriate length between a pair of devices that acts asan alignment and spacing guide for application to the neck.

FIG. 22 is an illustration of another embodiment of the presentinvention that applies pressure on appropriate positions on the neckwithout the use of a circumferential collar. In this embodiment, thedevice comprises a U-shaped resilient band with a protuberance disposedon one or both ends.

FIG. 23 is an illustration of a circumferential collar type device ofthe present invention comprising a pull-away cable-tie type ratchetingfit adjustment system, wherein the pull-away cable-tie is configured torelease from the collar when pulled at or above a specific pressure.

FIG. 24 is an illustration of a circumferential collar type device ofthe present invention comprising a rotating ratchet fit adjustmentsystem and an external adjustment tool.

FIG. 25 is an illustration of a circumferential collar type device ofthe present invention comprising a rotating ratchet fit adjustmentsystem with an integrated adjustment dial.

FIG. 26 is an illustration of circumferential collar type device of thepresent invention comprising one or more discernible graphic or tactilereference points on an exterior surface of the device to assistplacement and/or alignment on the wearer.

FIG. 27 is an illustration of another embodiment of the presentinvention wherein the device further comprises a sensor configured todetect pulse, blood pressure, or other indicia of proper placement andpressure of a protuberance above a neck vein, and means to transmit asignal from the sensor to an external device.

FIG. 28 is an illustration of another embodiment of the presentinvention wherein one or more protuberances are integral with a garment.

The drawings are described in greater detail in the description andexamples below.

DETAILED DESCRIPTION

The details of some exemplary embodiments of the methods and systems ofthe present disclosure are set forth in the description below. Otherfeatures, objects, and advantages of the disclosure will be apparent toone of skill in the art upon examination of the following description,drawings, examples and claims. It is intended that all such additionalsystems, methods, features, and advantages be included within thisdescription, be within the scope of the present disclosure, and beprotected by the accompanying claims.

Before the present disclosure is described in greater detail, it is tobe understood that this disclosure is not limited to particularembodiments described, and as such may, of course, vary. It is also tobe understood that the terminology used herein is for the purpose ofdescribing particular embodiments only, and is not intended to belimiting, since the scope of the present disclosure will be limited onlyby the appended claims.

When liquid in a tank or vessel experiences dynamic motion, a variety ofwave interactions and liquid phenomena can exist. The oscillation of afluid caused by external force, termed “sloshing”, occurs in movingvessels containing liquid masses. This sloshing effect can be a severeproblem in energy absorption, and thus, vehicle stability and control.The present disclosure encompasses methods and apparatus for reducingSLOSH effects in living creatures, and in particular in the intracranialand spinal regions of the animal or human subject.

The mitigation of blast wave and collision damage is based largely onthe principle of energy absorption of fluid-filled containers. As therebecomes more room for movement of fluid within a vessel, more energy canbe absorbed (SLOSH) rather than transmitted through the vessel. Toreduce this energy absorption, one must attempt to more closelyapproximate elastic collisions. Elastic collisions are those that resultin no net transfer of energy, chiefly, acoustic, kinetic, vibrational,or thermal (also stated as a coefficient of restitution (r)approximating 1.0). Various embodiments described below may locallyalter, elevate, or temporarily maintain an altered physiology of anorganism to reduce the likelihood of energy absorption through SLOSHwhereby the coefficient of restitution (r) is increased. The coefficientof restitution (r) indicates the variance of an impacting object awayfrom being a complete total elastic collision (an (r) of 1.0=no energytransfer). Blast or energy absorption in an organism can be viewed as acollision of bodies and thus be defined by a transfer of energiesthrough elastic or inelastic collisions. The mechanisms for biologicalfluids and molecules to absorb energy can thus be identified and theresultant means to mitigate that absorption can be achieved throughseveral SLOSH reducing techniques. Dissipation of energies post blast isalso potentiated through these techniques.

SLOSH absorption may be reduced by reversibly increasing pressure orvolume within the organs or cells of the organism. Applying this conceptto the contents of the skull, the intracranial volume and pressure canbe reversibly increased by a device that reduces the flow of one or moreof the cranial outflow vessels. One embodiment of such a device wouldcompress the outflow vessels enough to cause an increase in venousresistance, yet not enough to increase an arterial pressure leading intothe cranium above approximately 80 mm Hg.

Mitigating SLOSH by increasing the pressure of the fluid contents of thebrain can significantly reduce the propensity for damage to the braintissue or its blood vessels by reducing the compressibility of thebrain. The reduction in compressibility results in reduced absorption ofkinetic, acoustic, thermal, and vibrational energy by the brain.

Intracranial volume can also be reversibly increased by increasing thepCO₂ in the arterial blood or by the delivery of one or more medicamentsto facilitate an increase in intracranial volume or pressure includingbut not limited to Minocycline, insulin-like growth factor 1, Provera,and Vitamin A. Such techniques may be used in combination with use ofthe devices disclosed herein.

With respect to the inner ear, it is known that the cochlear aqueduct isin direct communication with the cerebrospinal fluid (CSF) and the veinof the aqueduct drains directly into the internal jugular vein (IJV).The venous blood empties either directly into the inferior petrosalsinus or internal jugular vein, or travels through other venous sinusesvia the vein of the vestibular or cochlear aqueduct. Reduced outflow ofthe internal jugular would necessarily congest the cochlear vein andtake up the compliance of the inner ear, thereby improving elasticcollisions at the macroscopic, cellular, and molecular level and, thus,reducing energy impartation into these structures.

Approximately 30 ml (21%) of a total CSF volume of 140 ml resides withinthe spinal axis, and about one-third of the compliance of the CSF systemhas been attributed to the spinal compartment. As in the brain,increasing the pressure and volume of the CSF within the spinalcompartment reduces the susceptibility of the spinal compartment toconcussive injuries by increasing the elasticity of the contents of thespinal column, thereby reducing the amount of energy absorbed by thecontents of the spinal column when subjected to a concussive force.

With respect to ocular injuries, it is known that the woodpecker has a“pectin apparatus” that protects the globe of its eyeball from the 1200Gimpact of pecking. The sole purpose of the pectin apparatus appears tobe to increase the volume and pressure of the vitreous humor inside theeyeball. The pectin apparatus is situated within the eyeball and fillswith blood to briefly elevate intraocular pressure, thereby maintainingfirm pressure on the lens and retina to prevent damage that mightotherwise occur during the 80 million pecking blows over the averagewoodpecker's lifetime. While humans lack the pectin apparatus, it ispossible to increase intraocular pressure by externally applyingpressure on the external jugular veins (EJV).

One aspect of the present invention, therefore, encompasses a devicethat raises intracranial volume and pressure and/or intraocular pressurewhen worn by a subject animal or human. The device is configured toapply pressure to the outflow vasculature in the neck (e.g., one or moreinternal and/or external jugular vein), thus increasing intracranialand/or intraocular pressures and volumes in the wearer. In doing so, thedevice reduces energy absorption by the wearer due to concussiveeffects, thus reducing the likelihood of one or more of brain, spine,and eye damage from a concussive event. Devices of the instant inventioncould be worn preferably before, in anticipation of and during eventswith SLOSH and traumatic brain injury risks.

Safely and reversibly increasing cerebral blood volume by any amount upto 10 cm³ and pressure by any amount up to 70 mmHg would serve to fillup the compliance of the cerebral vascular tree and thus reduce theability to absorb external energies through SLOSH energy absorption.With the application of measured pressure to the neck, the cranial bloodvolume increases rapidly and plateaus at a new higher level. Moyer et alreported that cerebral arterial blood flow was not affected byobstructing the venous outflow of blood from the brain. The blood volumevenous pressure relationship shows a diminishing increase in volume witheach increment of neck pressure over the range 40 to 70 mm of mercury.It is of interest that the cranial blood volume increases from 10 to 30percent (with this neck pressure). Similarly, CSF pressure alsoincreases upon compression of the individual jugular veins. Under thesame neck pressure, the average rise in CSF pressure is about 48%. Thesechanges occur very rapidly upon initiation of pressure; jugularcompression increases cerebral blood flow to a new plateau in as littleas 0.5 seconds. Although lesser cranial pressure and volume increasesmay still have beneficial effects, it is intended that devices of theinstant invention increase cranial blood volume by at least 3 cm³through an application of at least 5 mm Hg neck pressure. In someembodiments, the devices apply between about 5-70 mmHg, such as betweenabout 5-60 mmHg, such as between about 5-50 mmHg, such as between about5-40 mmHg, such as between about 5-30 mmHg, such as between about 5-20mmHg, such as between about 5-10 mmHg of pressure to the neck veins.

Devices of the present invention, therefore, may take many forms, butshare the functional feature of constantly or intermittently applyingpressure to one or more veins in the neck (specifically, but not limitedto the internal and external jugular veins, the vertebral veins, and thecerebral spinal circulation, and most preferably, the interior jugularvein) to restrict blood flow exiting the brain. Thus, the instantdevices include at least one inwardly directed protuberance that isinwardly directed and contacts the neck of the wearer of the device, andat least one means for applying pressure to the one or moreprotuberances such that the protuberances apply pressure to one or moreveins in the neck, thereby restricting blood flow exiting the brain.

Inwardly Directed Protuberances that Contact the Neck of the Wearer

In some embodiments, the one or more inwardly directed protuberances areintegral to the component of the device responsible for applyingpressure to the neck. In alternative embodiments, the one or moreinwardly directed protuberances are distinct from the component of thedevice responsible for applying pressure to the neck. Is to be generallyunderstood that the protuberances may be any suitable shape, e.g.,pointed or round, and comprising of any suitable material, such asdefined by a rigid or semi-rigid plastic body, a thickened region of acollar, and the like.

In some embodiments, the protuberances may substantially be defined by abladder, whereby pressure is exerted on the neck of the wearer when thebladder is inflated or filled. In some related embodiments, the bladdermay contain reversibly compressible foam that is in fluid communicationwith the external atmosphere. In further related embodiments, theinterior of the bladder is in fluid communication with the externalatmosphere via a pressure release valve. In embodiments comprising abladder, foam, and valve, these components may be configured so that thefoam expands within the bladder, drawing air into the bladder throughthe pressure valve to inflate the bladder to a desired pressure.However, the pressure release valve may be configured to allow forrelease of air from the bladder upon an application of pressure to thedevice that may otherwise raise the amount of pressure applied to theneck to an uncomfortable or undesirable level. In other embodiments, thebladder may contain a gas or liquid and may be outfitted or configuredto interface with a pump mechanism such that the pressure of the bladdermay be user adjusted. The pump mechanism may be any suitable pumpmechanism as would be understood in the art, such as e.g., a poweredpump, or a hand-compressible pump whereby a liquid, air or a gas can beapplied to the bladder. In certain embodiments the device may furthercomprise a pressure sensor operably linked to the pump mechanism orbladder whereby the degree of inflation may be regulated as to theextent and duration of the pressure applied to an underlying neck vein.

In some embodiments, the protuberance comprises a spring or resilientcompressible material. In these embodiments, the spring or resilientcompressible material is disposed within the protuberance such thatapplication of the protuberance to the neck at least partiallycompresses the spring or resilient compressible material. The forceexerted by the at least partially compressed spring or resilientcompressible material ensures that the protuberance maintains a desiredpressure on the neck.

In some embodiments, the device may comprise a resilient arcuate bandhaving a general C, V, or U-shape. The band may be formed of a resilientspring-like material whereby the C, V, or U-shaped band is forced openas the device is applied. After application of the device, springtension causes compression of the band, resulting in the mid-point orbend-point of the band to extend toward and apply pressure to the neck.Thus, in these embodiments, the mid-point or bend-point of the bands arethe protuberances that contact the neck of the wearer.

In some embodiments, at least a portion of an inwardly directed surfaceof the one or more protuberances may be coated with a suitable adhesiveto facilitate placement of the protuberances on the neck, and preventmovement of the protuberance once in place. Additionally or in thealternative, in embodiments where the protuberances are distinct fromthe component of the device which applies pressure to the neck, at leasta portion of an outwardly directed surface of the one or moreprotuberances may be coated with a suitable adhesive. In suchembodiments, the design of the device may such that a protuberance maybe paced between a component which applies pressure to the neck and theneck itself. An outwardly directed surface of the protuberance wouldthen contact an inwardly directed surface of the pressure-providingcomponent of the device such that the adhesive on the outwardly directedsurface of the protuberance would prevent movement of the protuberanceonce in place.

One exemplary embodiment of this type (discussed in greater detailbelow) comprises three pieces: two round or oval plastic protuberances(one for application to either side of the neck) and an elastic collar.The device could be applied by first putting the collar around the neck,and then by placing the plastic protuberances between the collar and theneck at the appropriate locations so as to apply pressure to theinternal jugular vein on either side of the neck. As will be appreciatedfor this example, a mild adhesive coating on the inwardly directedand/or outwardly directed surfaces of the protuberances will assist inpreventing movement of the protuberances once they are installed betweenthe collar and the neck. Alternately, if the protuberances have anadhesive coating of sufficient strength at least on the inwardlydirected surfaces, the protuberances may be placed on the appropriatelocations on the neck prior to installation of the collar. In eithercase, the collar applies pressure to the protuberances, which in turnapplies pressure to the neck veins.

In other embodiments of this type, two protuberances may be secured toone another with a tether of the appropriate length to act as analignment and spacing guide for application on either side of the neck.In some embodiments, the tether may be removable, so that once theprotuberances are applied to the neck, the tether may be pulled orotherwise removed, leaving the protuberances in place on the neck of thewearer.

In some embodiments, the protuberances are compressible pads or solidforms sized to apply pressure substantially only to the internal jugularvein.

Circumferential and Semi-Circumferential Collar Type Devices

In some embodiments, the device may be a circumferential orsemi-circumferential collar. A circumferential collar is a collar thatencircles the entire circumference of the neck when the device is wornby an animal or human subject. A semi-circumferential collar is a collarthat encircles a majority of the circumference of the neck when thedevice is worn by an animal or human subject. The portion of thecircumference of the neck that is not encircled by asemi-circumferential collar may be disposed at any location around thecircumference of the neck, so long as the encircled portion allows forapplication of pressure on inwardly directed protuberances specificallylocated in order to restrict blood flow exiting the brain. Typically,the open portion will be either located at the front of the throat(e.g., in some embodiments, a semi-circumferential collar may encirclethe neck except an area substantially defined by laryngeal prominence,also known as the “Adam's apple”), or located at the back of the neck.

In embodiments where the device comprises a circumferential collar, itis contemplated that the applied pressure to the neck may be due to aninternal dimension of the collar being less than the neck diameter. Thisdifference in internal dimension of the collar may be achieved by anynumber of configurations dictated by the materials used to construct thecollar. For instance, in a collar comprising inelastic materials, thecollar may be sized to apply the appropriate pressure when worn by anindividual. In these embodiments, the size of the collar may be suchthat the collar is tailored to an individual and thus requires noadjustment for fit. Alternatively, the size of the collar may beadjustable by any of a number of means, some of which are discussedfurther below. In some embodiments, the collar may comprise an elasticmaterial such that the internal dimension of the elastic collar isexpanded when the collar is worn, and the collar applies pressure to theneck of the wearer as a result of compressive force exerted by theexpanded elastic material. Elastic materials may also confer the benefitof increased comfort for the wearer.

In embodiments where the device comprises a semi-circumferential collar,it is contemplated that the collar comprises a resilient arcuate bandhaving a general C, V, or U-shape. In these embodiments, it is intendedthat the band extend a majority, if not the entirety, of the length ofthe collar. In these embodiments, the collar thus semi-rigidly defines aC, V, or U-shape that is expanded as the collar is applied to the neckof a wearer. Spring tension from the expanded resilient arcuate bandcauses a compressive force that keeps the collar in place on the neckand applies the intended pressure to the neck veins.

In these embodiments, at least one inwardly directed pad or form may bedisposed at appropriate locations on opposing sides of the collar, suchthat the inwardly directed pads or forms are configured to contact theneck and apply pressure to a point above the interior jugular vein. Inembodiments where the semi-circumferential collar is open at the frontof the throat, the area of the neck not covered by thesemi-circumferential collar may define a region approximating thelaryngeal prominence, also known as the “Adam's apple.” In theseembodiments, the inwardly directed pad or forms disposed on opposingsides of the collar may be located at or near the terminal ends of theresilient arcuate band. In embodiments where the semi-circumferentialcollar is open at the back of the neck, the inwardly directed pads orforms may not be disposed near the terminal ends, but rather may bedisposed much closer to the mid-point of the band.

In some embodiments where the device comprises a circumferential collaror a semi-circumferential collar that is open at the back of the neck,the device may comprise a laryngeal bridge that defines a cut-out at thefront of the neck. The size and shape of the laryngeal bridge may beconfigured so as to minimize contact of the collar with the laryngealprominence in order to make the collar more comfortable for the wearer.In these embodiments, the laryngeal bridge may be of any suitablematerial as to provide a rigid or semi-rigid continuation of the collararound the front of the neck. In some embodiments, the laryngeal bridgemay comprise thick or reinforced textile material, plastic, metal, orany combination thereof.

In some embodiments where the device comprises a circumferential collar,the device comprises two components: a front section comprising the oneor more inwardly directed protuberances and a laryngeal bridge, and aback section comprising a length of fabric configured to be removablyattached at either end to corresponding ends of the front section. Insome embodiments, the length of fabric comprises an elastic material;alternatively, the length of fabric may comprise an inelastic fabric.Removable attachment of either end of the front section to thecorresponding end of the back section may be by any suitable methodknown in the art, such as a hook and ladder attachment, a hook and loopattachment, a snap, a button, a chemical adhesive, or any of a number ofattachment mechanisms that would be known to one skilled in the art. Adevice with removable attachment means could also have a breakawayrelease mechanism whereby the device can break open or apart at apredetermined force to prevent the device from inadvertently beingsnagged or compressing too tightly.

Many of the devices described herein are described as potentiallycomprising an elastic material. More particularly, it is intended thatthese devices may comprise materials that are elastically elongatablearound the circumference of a subject's neck. Elastic materials can beany material which when stretched will attempt to return to the naturalstate. Exemplary materials may include one or more of textiles, films(wovens, non-wovens and nettings), foams and rubber (synthetics andnatural), polychloroprene (e.g. NEOPRENE®), elastane and otherpolyurethane-polyurea copolymerss (e.g. SPANDEX®, LYCRA®), fleece, warpknits or narrow elastic fabrics, raschel, tricot, milanese knits, satin,twill, nylon, cotton tweed, yarns, rayon, polyester, leather, canvas,polyurethane, rubberized materials, elastomers, and vinyl. There arealso a number of elastic materials which are breathable or moisturewicking which may be preferable during extended wearing periods orwearing during periods of exercise. As indicated above, elasticmaterials may confer the benefit of increased comfort for the wearer byproviding sufficient compressive pressure, yet remaining flexible toaccommodate a full range of motion and/or muscle flex in the wearer.

In addition, a device constructed with an elastic material may bepartially reinforced, coated, or otherwise include one or moreprotecting materials such as KEVLAR (para-aramid synthetic fibers),DYNEEMA® (ultra-high-molecular-weight polyethylene), ceramics, or shearthickening fluids. Such reinforced materials may confer the benefit ofincreasing the devices resistance to lacerations. As such, reinforceddevices may provide the user the added benefit of protecting the neckfrom damage from lacerations.

In some embodiments, circumferential or semi-circumferential collars maybe constructed with materials, elastic or otherwise, that are fireresistant.

The device may encompass horizontally, the entire neck or just partiallyup and down the neck. The width of the devices described herein mayrange from a mere thread (at a fraction of an inch) to the length of theexposed neck (up to 12 inches in humans or greater in other creatures),the length may range from 6 to 36 inches to circumnavigate the neck. Thewidth of the compression device could be as small as ¼ inch but limitedonly by the height of the neck in largest width, which would betypically less than 6 inches. The thickness of said device could rangefrom a film being only a fraction of a millimeter to a maximum of thatwhich might be cumbersome yet keeps ones neck warm, such as 2-3 inchesthick.

One embodiment of the device may be pre-formed for the user in acircular construct. This one size fits all style can have a cinch ofsorts that allows one to conform the device to any neck size.Alternatively the device may have a first end and a second end which areconnected by a fastener. A fastener may be magnetic, a tack strip, ahook and ladder attachment, a hook and loop attachment, a ply strip, oneor more slide fasteners, one or more zippers, one or more snaps, one ormore buttons, one or more safety pin type clasp mechanisms, overlappingelectrostatic contact materials, or any of a number of attachmentmechanisms that would be known to one skilled in the art. A device witha fastener could have a breakaway release mechanism whereby the devicecan break open or apart at a predetermined force to prevent the collarfrom inadvertently being snagged or compressing too tightly. One quickrelease or automatic release embodiment would be the applying of smallamounts of hook and ladder attachments within a circumferential ringwhich would shear apart upon too much force being applied to the device.

Another embodiment of the device could fasten such that the user wouldbe able to pull one end of the collar (like a choker collar for a dog)and the force exerted by the user effectually decreases the length orcircumference of the device. When the desired neck compression is nolonger needed (such as between football plays) the user could thenrelease the compression by a second gentle tug or by a separate releasemechanism also positioned on the device.

Other fit adjustment systems may be used in the collar-type devicesdescribed herein. For example, in one embodiment, a pull-away cable-tie(e.g., ZIP-TIE®) type ratcheting fit adjustment system may be included.This type of system may include one or more pull-away cable-tiesconfigured to release from the collar when pulled at or above a specificpressure, thus ensuring that the collar is hot over tightened. Inalternate embodiments, a rotating ratcheting fit adjustment system maybe included. In such embodiments, system may be designed such that anexternal tool is employed fit adjustment. Preferably, such systemsutilize elastic materials and or an adjustable fastener system (asdescribed above) such as a VELCRO® closure-system to provide a gross-fitof the device. The ratcheting adjustment system would then be used forfine-adjustments of the device specific for an individual wearer. As analternative to an external tool system, rotating ratchet fit adjustmentsystems which include an integrated adjustment dial, e.g., a BOA®rotating ratchet fit adjustment system as described in U.S. Pat. No.8,381,362 and U.S. Pat. Pub. No. 2012/0246974.

In some embodiments, a circumferential or semi-circumferential collarmay comprise a shape memory polymer. In such embodiments, the collarwould be applied to the neck of a user, then the appropriate stimuluswould be applied to the shape memory polymer, causing the collar toshrink to fit.

In some embodiments, a circumferential or semi-circumferential collarmay comprise a bladder whereby the pressure exerted on the neck of thewearer by the collar may be adjusted by inflating or deflating thebladder. In some related embodiments, the bladder may contain reversiblycompressible foam that is in fluid communication with the externalatmosphere. In further related embodiments, the interior of the bladderis in fluid communication with the external atmosphere via a pressurerelease valve. In embodiments comprising a bladder, foam, and valve,these components may be configured so that the foam expands within thebladder, drawing air into the bladder through the pressure valve toinflate the bladder to a desired pressure. However, the pressure releasevalve may be configured to allow for release of air from the bladderupon an application of pressure to a protuberance that may otherwiseraise the amount of pressure applied to the neck to an uncomfortable orundesirable level. In other embodiments, the bladder may contain a gasor liquid and may be outfitted or configured to interface with a pumpmechanism such that the pressure of the bladder may be user adjusted.The pump mechanism may be any suitable pump mechanism as would beunderstood in the art, such as e.g., a powered pump, or ahand-compressible pump whereby a liquid, air or a gas can be applied tothe bladder. In certain embodiments the device may further comprise apressure sensor operably linked to the pump mechanism or bladder wherebythe degree of inflation may be regulated as to the extent and durationof the pressure applied to an underlying neck vein. In some embodiments,the bladder is disposed to at least include a portion of the collarother than above a protuberance. In some embodiments, the bladder isdisposed through a majority of the circumference of the collar.

In some embodiments, a circumferential or semi-circumferential collarmay further comprise a pouch or pocket. This pouch or pocket may beexternally accessible, i.e., accessible while the collar is being worn,or only accessible when the collar is removed. The dimensions of such apouch or pocket may be such that the pouch or pocket is suitable tocarry one or more items useful for the treatment of TBI relatedcalamities, such as a material enabling CO₂ delivery, carbonic anhydrasetablets, methylene blue, DHA, smelling salts, etc.

In some embodiments, a circumferential or semi-circumferential collarmay further comprise an electrical circuit comprising a piezoelectricheat pump configured to alter the temperature of the inwardly directedsurface of the collar. Such a heat pump may be used to either heat orcool the device, for example by as much as 70° from ambient temperature.

In some embodiments, a circumferential or semi-circumferential collarmay further comprise an electrical circuit configured to provide atherapeutic electrical stimulation to the neck of the wearer. Forexample, an electrical circuit may be configured to providetranscutaneous electrical nerve stimulation.

Non-Collar Type Devices

In some embodiments, the device may be a non-collar type device.Non-collar type devices are those that cover or encircle a minority ofthe circumference of the neck when the device is worn by an animal orhuman subject. However, the portion of the circumference of the neckthat is covered or encircled by non-collar type devices must at leastinclude one or more areas of the neck above a neck vein, as describedabove. As with collar-type devices, non-collar type devices also utilizeinwardly directed protuberances to apply pressure to the neck atspecific locations in order to restrict blood flow exiting the brain.Any of the protuberances described above may find use in non-collar typedevices.

In some embodiments, the externally directed side of a protuberance maybe covered by flexible material that extends beyond the area defined bythe protuberance. In these embodiments, at least a portion of thisextended inwardly directed surface contacts the neck when the device isin place. In some embodiments, the at least a portion of the inwardlydirected surface of the flexible material that contacts the neck iscoated with an appropriate adhesive, such that when applied to the neck,the flexible material holds the protuberance in an appropriate positionand applies pressure to a neck vein. The flexible material may beelastic or non-elastic. The flexible material may be any suitablesynthetic or natural woven or textile material, or any suitable plastic.

Such embodiments may comprise a pair of material/protuberancecombinations for application to both sides of the neck. Some relatedembodiments may comprise a pair of material/protuberance combinationsjoined by a tether, as described above. The tether may be of appropriatelength so as to serve as an aid to alignment and proper placement of theprotuberances at the correct locations on the neck. In some embodiments,the tether may be removably attached to the pair ofmaterial/protuberance combinations so that after placement of theprotuberances on either side of the neck, the tether is removed.

In some non-collar type devices, the device may comprise a resilientarcuate band having a general C, V, or U-shape. In these embodiments, itis intended that a protuberance is located at or near the terminus ofeach arm of the band, and that when the device is in place, the bandextends around the front of the neck. In these embodiments, the bandthus semi-rigidly defines a C, V, or U-shape that is expanded as thedevice is applied to the neck of a wearer. Spring tension from theexpanded resilient arcuate band causes a compressive force that keepsthe device in place on the neck and applies the intended pressure to theneck veins via the protuberances. In some embodiments, the resilientarcuate band is sized and shaped such that it does not cross the frontof the neck in the general area of the laryngeal prominence. Instead,the band may cross the front of the neck at a position below thelaryngeal prominence.

Garments or Other Protective Gear Comprising Integral Protuberances

In yet other embodiments, it is envisioned that protuberances (asdescribed above) may be incorporated into various articles of clothingand/or other protective gear. Such garments and/or other protective geartypically may be designed for specific purposes, e.g., as part of amilitary uniform, sporting apparel, neck guard for first responders,flame retardant head gear for automobile or motorcycle drivers orfirefighters, etc. In any case, protuberances may be included at theappropriate positions in a portion of a garment or protective gear thatcontacts the neck of the wearer, i.e., the collar, with the collarproviding compressive force on the protuberances. As such, any of theclosing, alignment, or fitting means, or any other optional featureprovided in regards to circumferential or semi-circumferentialcollar-type devices may be incorporated in garment and/or protectivegear embodiments.

In some embodiments, at least the collar of the garment comprises anelastic material.

Visual or Tactile Alignment Aids

Any of the embodiments described above may further comprise one or morematerials, and/or apply one or more construction methods, designed toprovide the user or a 3^(rd) party observer with a visual or tactile aidin determining proper alignment and positioning of the protuberances.For instance, a collar type device may include a small strip or patch ofa contrasting or reflective material, or a material with a differenttexture, at the mid-point of the neck. Alternatively or in addition,similar visual or tactile cues may be incorporated into any of the abovedevices so as to provide an outward indication of the location of aprotuberance.

Further, any of the embodiments described above that utilize elasticmaterials may comprise a dual layered elastic material that exposes achange in graphic or color when sufficiently stretched to apply anappropriate force on an underlying protuberance. In such embodiments,the change in graphic or color may provide a visual cue to the wearer or3^(rd) party observer that the device is applying at least sufficientcompressive force.

Incorporated Sensors or Other Electronic Systems

Any of the above devices may also have one or more monitoring,recording, and/or communicating devices attached or embedded. Forexample, the device may comprise a sensor capable of detecting one ormore environmental parameters around the wearer, one or morephysiological parameters of the wearer, or some combination thereof.Exemplary environmental parameters that may be detected include time thecollar has been worn, barometric pressure, ambient temperature,humidity, acceleration/decelration (i.e., G forces), positionality(upright/supine), etc. Physiological parameters that may be detectedinclude pulse, blood pressure, plethysmography, dermal temperature,oxygen saturation, carboxyhemoglobin level, methemoglobin level, bloodsugar, electrical flow, etc. of the human or animal wearing the device.Any of such sensors may be used to monitor some environmental orphysiological characteristic or performance aspect of the wearer.Sensors capable of detecting pulse, blood pressure, and/orplethysmography may serve the additional or alternate purpose of beingused as an alignment and/or fit aid, notifying the user when theprotuberance is properly placed over a neck vein and is exerting anappropriate pressure so as to restrict blood flow.

In some related embodiments, a device may further comprise an electroniccircuit capable of providing visual, auditory, or tactile indicia ofmalfunction, or an undesirable sensor reading. For instance, anelectronic circuit may be configured to vibrate the collar when a pulseor blood pressure sensor detects a reading that is either higher orlower than a predetermined value.

Additionally or in the alternative, any of the above devices maycomprise an electronic circuit configured to transmit the location ofthe wearer. For instance, any of the above devices may comprise anelectronic circuit configured to transmit the GPS coordinates of thewearer for tracking the location of the wearer, or for search and rescuepurposes.

Additionally or in the alternative, any of the above devices maycomprise an electronic circuit configured to transmit and/or receivevoice communications between the wearer and a third party.

In some embodiments, the output of such a sensor may be visually oraudibly communicated to the user or a 3^(rd) party by another componentof the device, e.g., an electronic circuit configured to provide avisual or auditory indication (such as with an LED, piezoelectricspeaker, etc.). In some embodiments, the device further comprises acommunication means such that a signal from the sensor may becommunicated to an external electronic device, such as a smartphone,laptop, or dedicated receiver.

These terms and specifications, including the examples, serve todescribe the invention by example and not to limit the invention. It isexpected that others will perceive differences, which, while differingfrom the forgoing, do not depart from the scope of the invention hereindescribed and claimed. In particular, any of the functional elementsdescribed herein may be replaced by any other known element having anequivalent function.

EXEMPLARY EMBODIMENTS

Particular embodiments of a collar type device are illustrated in FIGS.1-3. Referring to FIGS. 1( a)-(c), a compression collar 10 includes anelongated strap 12 that may be provided in various sizes to encircle theneck of the animal or human subject. In one specific embodiment thestrap may be provided in standard lengths of 14, 16 and 18 inches to fitthe normal range of neck sizes for humans. The width in a specificexample may be about 1.5 inches to fit within the anatomy of the neckbelow the laryngeal prominence. To minimize the prominence of thecollar, the strap may have a thickness of about 0.12 inches. The strap12 may be formed of a woven, breathable, dermatologically inert andnon-irritating material, such as cotton or certain polyesters. Since thestrap is intended to apply consistent pressure to the jugular vein ofthe subject the strap material is preferably generally elastic, butformed of an elastic material that will not permanently stretchappreciably over time. It can be appreciated that stretching thematerial so that the neutral length of the strap is longer than itsoriginal condition can render the strap 12 useless. On the other hand,the strap material must be sufficiently elastic or elasticallyelongatable to remain comfortable when worn for a long period of time,and to flex appropriately with the muscles of the neck. The effectivelength of the strap 12 is made adjustable by the addition of adjustableengagement elements 16 and 18 at opposite ends of the strap. Forinstance, in the embodiment shown in FIG. 1( a) the latch element 16defines a serrated channel 16 a that receives the resilient prongs 18 aof the other element. The prongs 18 a are biased to provide an outwardforce against the channel 16 a of the latch to hold the prongs at thelocation of a particular serration 16 b. In the illustrated embodiment,seven serrations are depicted which provide seven locations forengagement of the prongs 18 a for fine adjustment of the length of thecollar. The two components 16, 18 may be sewn onto the strap 12 orpermanently affixed in a conventional manner sufficient so that theengagement elements will not pull free from the strap during use.

Two versions of the collar are depicted in FIGS. 1( a) and 1(b). Theversion of FIG. 1( a) is provided for a male human and includes acut-out 14 at the location of the laryngeal prominence. The strap 12 ofFIG. 1( b) does not include the cut-out and may be typically providedfor female human subjects. The cut-out may have a width of about 1.5inches and a depth of about 0.5 inches to accommodate the typicallaryngeal prominence. It can be appreciated that the collar 10 isengaged around the neck of the subject so that the cut-out 14 is belowand sufficiently clear of the prominence to avoid any discomfort to thesubject.

In a further feature of the collars 10, 10′, a pair of compressible pads20 are provided spaced apart across the midline of the strap 12, 12′.The pads are sized and located to bear against the neck at the locationof the jugular veins. In one embodiment the pads are spaced apart byabout 2.5 inches, have a width/length dimension of 1.0-1.5 inches and athickness of about 0.04 inches. As shown in FIG. 1( c) the pads may bepartially embedded within the strap 12. The pads 20 may be formed of abreathable foam that exhibits good recovery from compression. The padsmay be formed of a material capable of exerting compression of 5-30 mmHg when the collar is worn, such as a flexible polyurethane foam.

Additional embodiments of the compression collar are shown in FIGS. 2and 3 that incorporate different engagement elements. For instance, thecollar 30 of FIG. 2 incorporates an array of snap pairs 36 at one endthat engage a pair of snaps 38 at the opposite end. The snap pairs 36may be spaced at pre-determined intervals, such as at ¼ inch spacings topermit adjustment of the collar diameter when worn. The collar 50 inFIG. 3 incorporates a row of hooks 56 at one end that engage acorresponding row of loops 58 at the opposite end. The embodiment ofFIG. 3 illustrates that the engagement elements need not be adjustable,although adjustability is preferred. In the embodiment of FIG. 3 thisadjustability may be accomplished by a VELCRO® type connection betweenthe strap 52 and the row of loops 58. In particular, a VELCRO® type padinterface 59 may be used to mount the loops 58 to the strap at differentpositions along the length of the strap. In a further alternative, theVELCRO® interface may be between the two ends with mating VELCRO® typepads on each end.

In one aspect of the compression collars disclosed herein, theengagement elements are preferably configured to break loose ordisconnect at a certain load, to avoid the risk of choking or damagingthe subject's neck and throat if the collar is snagged or grabbed. Thus,the engagement elements 16, 18 of FIG. 1, the snaps 36, 38 of FIG. 2 andthe hook attachment 59 of FIG. 3 can be calibrated to disconnect whenthe collar is pulled with sufficient force. In a further embodiment, theengagement elements, such as snaps 36, 38, may be replaced by magnets ora magnet array. The magnets are strong enough to maintain the desiredpressure on the jugular veins when the collar is in use. The magnetstrength may be calibrated to break loose at a certain load. Thebreak-away feature may also be integrated into the strap apart from theengagement elements. For instance, the strap may incorporate a regionbetween a pad 20 and an engagement element that has a reduced strengthso that the strap tears under a certain load. Alternatively, anon-adjustable engagement may be provided in this region calibrated todisengage at a predetermined load.

In the embodiments of FIGS. 1 and 3, the jugular vein is compressed bythe pad 20. The pad has a predetermined thickness and compressibility.In an alternative embodiment, the pads are replaced by inflatablebladders 40, as shown in FIG. 2. In this embodiment a fluid line 46connects the bladders to a pump 42 and a release valve 44. The pump 42can be of the type that is manually squeezed to draw atmospheric airinto the bladders. A one-way valve 43 is provided in the fluid line 46at the pump 42 to maintain the increasing air pressure within thebladders. The pump 42 may be constructed similar to a small engineprimer bulb. The pump may be configured to be manually depressed whilethe collar is being worn. The release valve 44 may be manually activatedto relieve the bladder pressure. The release valve may also beconfigured to automatically vent when a certain pressure is reached toprevent over-inflating the bladders 40.

In an alternative embodiment the pump 42 may be a microfluidic pumpembedded within the strap 32. The pump may be electrically powered by abattery mounted within the collar or may be remotely powered such as byan RF transmitter placed adjacent the collar. The pump may be remotelycontrolled by incorporating a transmitter/receiver within the collar.The receiver may transmit pressure data indicating the fluid pressure inthe bladders 40 and the receiver can receive remotely generated commandsto activate the pump 42 to increase the pressure to an appropriatevalue. It is further contemplated that the pump 42, whether manually orelectrically operated, may include a pressure gage that is readable onthe outside of the collar to assist in inflating the bladders to thedesired pressure.

The illustrated embodiments contemplate a collar that completelyencircles the neck of the subject. Alternatively the compression devicemay only partially encircle the neck. In this embodiment the device maybe a resilient arcuate band having a general C-shape. The band may beformed of a resilient spring-like material with the compression padsmounted to the ends of the C-shape. The device would thus function likea spring clip to exert pressure against the jugular vein. The springeffect of the C-shape can also help hold the device on the subject'sneck, preferably on the back of the neck for better anatomic purchase.

A compression collar 60, shown in FIG. 4, may incorporate a visualcompression indicator that can be visualized when the collar is fittedon a user. The collar 60 includes a strap 62 that may be configured likethe straps 12, 32, 52 described above, and may incorporate compressionpads 20, 40 arranged to apply pressure to the jugular vein when thestrap encircles the neck of the subject. The strap 62 is elastic so thatthe strap must be elongated or stretched when worn to apply the desiredpressure to the IJV. The strap 62 includes an array 65 of stripes 66, 67of alternating colors. For example, the stripes 66 may be red (tosignify a no-go condition) while the stripes 67 may be green (to signifya go condition). The compression collar 60 further includes an overlay70, shown in FIG. 5, which includes a number of windows 72. The stripes66, 67 and windows 72 are in like numbers (four in the illustratedembodiment), have the same width and are spaced apart the samedimension. In one specific embodiment the stripes 66, 67 have a width of2 mm, while the windows 72 have a width of 2 mm and are spaced apart by2 mm.

As shown in FIG. 6, the overlay 70 is fastened at one end 75 to thestrap 62. The opposite end 76 is not fastened to the strap to therebypermit the strap to stretch beneath the overlay. In the embodimentsdescribed above the entire strap is elastically elongatable. For thecompression indicator at least the portion of the strap in the region ofthe overlay 70 must be elastic and able to elongate or stretch relativeto the overlay. The overlay 70 is affixed to the strap 62 so that all ora substantial portion of the “no-go” stripes 66 are visible in thewindows 72 when the strap is in its neutral, unstretched configuration(i.e., before the collar is fitted to the subject), as shown in FIG. 7(a). When the collar is fastened around the subject's neck it willstretch and as it stretches the stripes 66, 67 advance relative to thewindows 72 of the overlay 70. Thus, as shown in FIG. 7( b), a portion ofboth stripes 66, 67 will be visible through the windows. When the strapis stretched a predetermined amount to apply the desired pressure to theIJV, the “go” stripes 67 will be fully or substantially visible in eachwindow 72, as shown in FIG. 7( c). If the strap is stretched too much,the “no-go” stripes 66 will again be visible in the windows. Thecompression indicator achieved by the stripe array 65 and overlay 70thus provides a direct visual indicator as to whether the collar isapplying the desired amount of pressure to the IJV. The collar may beadjusted so that the “go” stripes 67 are visible by adjusting theengagement elements, or by using a collar having a different startinglength. For instance, for the collar 30 of FIG. 2, a different row ofsnaps 36 may be mated to the snaps 38 to achieve the desiredcompression.

In the embodiment of FIGS. 4-7, the array 65 includes four sets ofparallel stripe pairs 66, 67. However, other visual indicia in anynumber of pairs may be utilized with appropriate modifications to thewindows 72 of the overlay. For instance, a the array 65 may includevisual indicia “GO” and “NOGO” or other words suitable to convey whenthe collar 60 is applying an appropriate amount of pressure to the IJV.Alternatively, the array may include a single indicia that is visiblethrough a single window in the overlay when the collar is properlyadjusted around the neck of the subject. The compression indicator ispreferably oriented on the collar at a location that is visible to thesubject when looking at a reflective surface. Alternatively, the indiciaon the strap 62 may be a tactile indicator that can be felt by thesubject's finger through the window(s) in the overlay.

Another aspect of the disclosure encompasses embodiments of a method ofincreasing the intracranial pressure of an animal or human subjectcomprising: (i) encircling the neck of an animal or human subject with acollar, wherein said collar has at least one region inwardly directed tocontact the neck of an animal or human subject; (ii) positioning the atleast one region inwardly directed to contact the neck on a region ofthe neck overlying a neck vein carrying blood from the intracranialcavity of the subject; and (iii) applying pressure to the neck vein bypressing the at least one region against the neck. In certainembodiments, this compression can be as much as 25 mm Hg without anyside effects and without impacting the carotid artery. It is believedthat pressures as high as 80 mm Hg can be applied without endangeringthe jugular vein or carotid artery. For many applications of the method,the pressure applied to the neck vein, or jugular vein, can be 3-15 mmHg. Applying pressure to the jugular vein can increase ICP up to 30%above the baseline pressure to protect the intracranial cavity fromblast-related SLOSH effects without any side effects.

In accordance with one embodiment of the method, a compression collar,such as the collars 10, 10′, 30 and 50 are placed low on the neck of thesubject and more particularly between the collar bone and the cricoidscartilage or laryngeal prominence. This location is distant from thecarotid sinus which is higher on the neck, so application of pressure tothe neck will not compress the carotid artery. In the case of a malesubject, the cut-out 14 of the strap 12 is positioned directly beneaththe laryngeal prominence.

The collar may be pre-sized to the subject so that it automaticallydelivers the proper amount of compression when the ends of the collarare connected. Moreover, as explained above, the engagement elements(i.e., the latching elements 16, 18, the snaps 36, 38, the hooks 56, 58or the VELCRO® connection) may be configured to break away or disengageif the pressure exceeds a desired value. This break away feature mayalso be applied with the pump embodiment of FIG. 2 in which case thebladders 40 can be inflated until the elements become disengaged, atwhich point the valve 44 may be actuated to bleed off some pressure fromthe bladders prior to refitting the collar on the subject's neck. In thealternative embodiment of the pump discussed above in which the pump isprovided with a pressure gage, the bladders are inflated to the desiredpressure indicated on the gage. In most cases, the desired compressionprovided by the collar may be in the range of 15-20 mm Hg, althoughhigher pressures are well tolerated and may be indicated for certainsubjects.

It can be appreciated that the collar is only worn when the subject maybe exposed to a concussive event, such as a blast during a militarybattle or hard contact during a sporting activity. Once exposure to suchan event ceases the collar may be removed, although it may be beneficialto leave it in place until the subject is evaluated for concussiverelated trauma.

Referring now to FIG. 13, a single unitary circumferential collar 100 isshown. As the unitary circumferential collar 100 has no means of beingopened for placement on the wearer, it is intended that such a collar ismade of an elastic material that allows the interior dimension of thecollar to expand sufficiently to pass over the head of the wearer.

Referring now to FIG. 14, a circumferential collar type device 102 isshown with pad-like protuberances 103, and an adjustable fastener 104(such as a VELCRO® type-connection). The adjustable fastener allows forproper fit across a range of neck sizes. The collar type device 102 maybe made from elastic or inelastic materials.

Referring now to FIG. 15, a similar circumferential collar type device102 is shown with pad-like protuberances 103, and an adjustable fastener104 (such as a VELCRO® type-connection). The adjustable fastener allowsfor proper fit across a range of neck sizes. The collar type device 102may be made from elastic or inelastic materials, and further comprises asemi-rigid or rigid laryngeal bridge 105.

Referring now to FIG. 16, a circumferential collar type device 106 afirst piece (i.e., front section 107) and second piece (i.e., backsection 108). The front section 107 contains two protuberances 103 eachconfigured to apply pressure to a neck vein of a wearer. The backsection 108 comprises a fabric collar section 109 configured to beremovably attached (such as by VELCRO® type-connections) at either endto corresponding ends 110 and 111 of the front section 107. It isintended that the back section 108 may be made from elastic or inelasticmaterials. It is further intended that the front section 107 may furthercomprise a semi-rigid or rigid laryngeal bridge (not shown).

Referring now to FIG. 17 a circumferential collar type device 102 isshown with pad-like protuberances 103, and an adjustable fastener 104(such as a VELCRO® type-connection). The adjustable fastener allows forproper fit across a range of neck sizes. The collar type device 102 maybe made from elastic or inelastic materials. In this embodiment, the twopad-like protuberances 103 each comprise a bladder (not shown) and apressure release valve 112 configured to apply pressure to a neck veinof a wearer.

Referring now to FIG. 18, a semi-circumferential collar 113 with a frontopening is shown. As the semi-circumferential collar 113 is open in thefront 114, it is intended that the collar 113 comprises a rigid orsemi-rigid material, and that the collar 113 is worn by sliding thecollar onto the neck of the wearer from the back to the front.

Referring now to FIG. 19, a semi-circumferential collar 115 with a backopening 116 is shown. As the semi-circumferential collar 115 is open inthe back, it is intended that the collar 115 comprises a rigid orsemi-rigid material, and that the collar 115 is worn by sliding thecollar onto the neck of the wearer from the front to the back.

Referring now to FIGS. 20A-C, exemplary embodiments that apply pressureon appropriate positions on the neck without the use of acircumferential collar are shown. These embodiments are typically wornas pairs, with a device worn on either side of the neck. FIG. 20A showsthat each device comprises a pad-type protuberance 103 covered by aflexible material 117 that extends beyond the area defined by theprotuberance. If these devices are used without a collar, it is intendedthat at least a portion of the inwardly directed surface 118 of thematerial extending beyond the area defined by the protuberance is coatedwith an appropriate adhesive. An inwardly directed surface of theprotuberance 103 may also be coated with an appropriate adhesive. Inthese embodiments, the flexible material 118 may be elastic orinelastic. FIG. 20B shows a similar embodiment that differs by employinga resilient arcuate band 119 having a general C, V, or U-shape to form aprotuberance 120. As discussed above, the band may be formed of aresilient spring-like material whereby the C, V, or U-shaped band isstraightened as the device is applied. After application of the device,spring tension causes compression of the band, resulting in themid-point or bend-point of the band to extend toward and apply pressureto the neck. FIG. 20C shows the device illustrated in FIG. 20B furthercomprising a removable tether 121 between the pair of devices whichfacilitates the alignment and spacing of the devices during applicationto the neck.

FIG. 21 is an illustration of another embodiment of the presentinvention that applies pressure on appropriate positions on the neckwithout the use of a circumferential collar. The device shown in FIG. 21is similar to those of FIGS. 20A-B, but further includes a removabletether 121 of the appropriate length between a pair of devices 122. Eachdevice comprises a protuberance 103 and it is intended that one devicewill be applied to either side of the neck. The removable tether 121aids in alignment and spacing during application of the devices 122 tothe neck.

FIG. 22 is an illustration of another embodiment of the presentinvention that applies pressure on appropriate positions on the neckwithout the use of a circumferential collar. In this embodiment, thedevice comprises a U-shaped resilient band 123 with a protuberance 103disposed at or near each end. In some embodiments, the protuberances 103may be integral to the resilient band 123. The embodiment shown in FIG.22 is of an alternate design, where the protuberances 103 are integralinto devices 122, which are attached at either end of the resilient band123. The U-shaped resilient band 123 is of the appropriate size andshape, and is appropriately resistant to bending, such that when theband is bent open, the protuberances 103 can be placed on the neck theappropriate locations and the band exerts sufficient compressive forceso as to reduce venous blood flow from the head.

FIG. 23 is an illustration of a circumferential collar type device ofthe present invention comprising a pull-away cable-tie type ratchetingfit adjustment system. In the shown device, the pull-away cable-tie 124is configured to release from the collar 125 when pulled at or above aspecific pressure, thus ensuring that the collar 125 is not overtightened.

FIG. 24 is an illustration of a circumferential collar type device ofthe present invention comprising a rotating ratchet fit adjustmentsystem and an external adjustment tool. In this embodiment, the fit ofcollar 125 is adjusted with an integral cable system 126. An externaltool 127 is used to shorten or lengthen the integral cable 126, therebyallowing for fine control of fit adjustment.

FIG. 25 is an illustration of a circumferential collar type device ofthe present invention comprising a rotating ratchet fit adjustmentsystem with an integrated adjustment dial. Similar to the embodimentdescribed above, the fit of collar 125 is adjusted with an integralcable system 126. In this embodiment, however, an internal ratchetingdial 128 is used to shorten or lengthen the integral cable 126, therebyallowing for fine control of fit adjustment.

FIG. 26 is an illustration of circumferential collar type device of thepresent invention comprising one or more discernible graphic or tactilereference points on an exterior surface of the device to assistplacement and/or alignment on the wearer. As described above, thegraphic or tactile reference points may be of any suitable design and/ormaterial. In the exemplary embodiments shown in FIG. 26, the graphic ortactile reference points may be placed so as to indicate the mid-pointof the device for alignment at the center of the front of the neck(e.g., shown with fabric patch 130), indicate the location of theprotuberances (e.g., shown with fabric patches 132), or both (shown withfabric trace 131).

FIG. 27 is an illustration of another embodiment of the presentinvention wherein the device 135 further comprises a sensor (notnumbered) configured to detect pulse, blood pressure, or other indiciaof proper placement and pressure of a protuberance above a neck vein,and means to transmit a signal from the sensor to an external device136.

FIG. 28 is an illustration of another embodiment of the presentinvention wherein one or more protuberances 103 are integral with agarment 137. The protuberances 103 may be incorporated into a portion ofa garment 138 that covers a portion of the neck of a wearer. Preferably,the portion of the garment 138 covering the portion of the neck of thewearer comprises an elastic material such that the collar of the garmentexerts sufficient pressure on the protuberances 103 so as to reducevenous blood flow from the head. While not intending to be limiting, itis envisioned that garments designed for various specialized purposes,such as components of military uniforms or sporting apparel, may beconstructed according to these embodiments.

Example 1 Materials and Methods

Two groups of ten (total of 20) male Sprague-Dawley rats weighingbetween 350 and 400 grams were used. Animals were housed under 12 hourlight/12 hour dark conditions with rat chow and water available adlibitum.

Marmarou Impact Acceleration Injury Model in Rats:

Anesthesia was induced and maintained with isoflurane using a modifiedmedical anesthesia machine. Body temperature was controlled during theapproximately 10 min. procedures using a homeothermic heating blanketwith rectal probe, and adequate sedation was confirmed by evaluation ofresponse to heel tendon pinch. The animals were shaved and prepared insterile fashion for surgery, followed by subcutaneous injection of 1%lidocaine local anesthetic into the planned incision site. A 3 cmmidline incision in the scalp was made and periosteal membranesseparated, exposing bregma and lambda. A metal disk 10 mm in diameterand 3 mm thick was attached to the skull with cyanoacrylate and centeredbetween bregma and lambda.

The animal was placed prone on a foam bed with the metal disk directlyunder a Plexiglas tube. A 450-g brass weight was dropped a single timethrough the tube from a height of 2 meters, striking the disk. Theanimal was then ventilated on 100% oxygen while the skull was inspected,the disk removed, and the incision repaired. When the animal recoveredspontaneous respirations, anesthesia was discontinued and the animal wasreturned to its cage for post-operative observation. Buprenorphine wasused for post-operative analgesia.

Example 2 Experimental Protocol

This work involved two groups, each consisting of 10 animals for a totalof 20 animals. Two groups were utilized, a control injury group and anexperimental injury group. In the experimental injury group the ratswere fitted with a 15 mm wide collar, with two compressive beadsdesigned to overlay the IJVs and was tightened sufficiently to providemild compression of the veins without compromising the airway. Thecollar was then fixed in circumference with a Velcro fastener. Thecollar was left in position for three minutes prior to administratingexperimental brain injury.

Assessment of Intracranial Reserve Volume Intracranial Pressure (ICP)Measurement:

ICP was measured in five animals using the FOP-MIV pressure sensor (FISOTechnologies, Quebec, Canada) as described by Chavko, et al. The head ofthe rat was shaved and prepped in sterile fashion for surgery. The ratwas fixed in a stereotaxic apparatus (model962; Dual Ultra Precise SmallAnimal Stereotaxic Instrument, Kopf Instruments, Germany) and a 3 cmmid-line incision in the scalp was made. Periosteal membranes wereseparated, exposing both bregma and lambda. A 2 mm burr hole was drilled0.9 mm caudal from bregma and 1.5 mm from the midline. The fiber opticprobe was then inserted to a depth of 3 mm into the cerebral parenchyma.

Intraocular Pressure (IOP) Measurement:

IOP was measured in all animals using the TonoLab rebound tonometer(Colonial Medical Supply, Franconia, N.H.) as described in theliterature, IOP measurements were taken after induction of anesthesia inall animals and a second time in the experimental group followingapplication of the IJV compression device. Following application of theIJV compression device in the experimental injury group, IOP readingswere taken every 30 secs while the compression device was in place.

Tissue Preparation and Immunohistochemical Labeling:

At 7 days post-injury all animals (n=20) were anesthetized andimmediately perfused transcardially with 200 ml cold 0.9% saline to washout all blood. This was followed by 4% paraformaldehyde infusion inMillings buffer for 40 mins. The entire brain, brainstem, and rostralspinal cord were removed and immediately placed in 4% paraformaldehydefor 24 hours. Following 24 hours fixation, the brain was blocked bycutting the brainstem above the pons, cutting the cerebellar peduncles,and then making sagittal cuts lateral to the pyramids. The resultingtissue, containing the corticospinal tracts and the mediallenmisci,areas shown previously to yield traumatically injured axons, was thensagitally cut on a vibratome into 50 micron thick sections.

The tissue underwent temperature controlled microwave antigen retrievalusing previously described techniques. The tissue was pre-incubated in asolution containing 10% normal serum and 0.2% Triton X in PBS for 40mins. For amyloid precursor protein (APP) labeling, the tissue wasincubated in polyclonal antibody raised in rabbit against beta APP(451-2700, Zymed, Inc., San Francisco, Calif.) at a dilution of 1:200 in1% NGS in PBS overnight. Following incubation in primary antibody, thetissue was washed 3 times in 1% NGS in PBS, then incubated in asecondary anti-rabbit IgG antibody conjugated with Alexa 488 fluorophore(Molecular Probes, Eugene, Oreg.), diluted at 1:200 for two hours. Thetissue underwent a final wash in 0.1 M phosphate buffer, and then wasmounted using an antifade agent and cover-slipped. The slides weresealed with acrylic and stored in the dark in a laboratory refrigerator.

Fluorescent Microscopy and Image Analysis:

The tissue was examined and images acquired using a Olympus AX70fluorescence microscope system (Olympus; Tokyo, Japan). Ten digitalimages were obtained from the tissue of each animal and images were thenrandomized. Individual injured axons were independently counted and datawas stored in a spreadsheet (Microsoft Corp., Redmond, Wash.).Differences between group means were determined using paired t-tests andconsidered significant if the probability value was less than 0.05.

Stereological Quantification of Axonal Injury:

A stereo logical method was used to determine an unbiased estimate ofthe number of APP positive axons per cubic mm in the corticospinal tractand medial lemniscus. The optical fractionator technique utilizing aStereoinvestigator 9.0 (MBF Bioscience, Inc., Williston, Vt.) and aOlympus AX70 microscope with 4× and 40× objectives was performed.Sagittal APP stained specimens were examined with low magnification andregions of interest were drawn incorporating the corticospinal tract andmedial lemniscus. The software then selected random 50 micron countingframes with depth of 15 microns, and APP positive axons were marked. Thevolume of the region of interest (ROI) was determined using theCavalieri method, the volume of the sum of the counting frames wascalculated, the sum total of injured axons within the counting frameswas calculated, and an estimate of the number of APP positive axons percubic mm was calculated.

Example 3 Volume Intracranial Pressure (ICP) Measurement

ICP was assessed both prior to and after application of the IJVcompression device. The baseline ICP was 10.23±1.68 mm Hg and wasincreased to 16.63±2.00 mm Hg following IJV compression (FIG. 8:p<0.01). Notably, this increase of greater than 30% from baselineoccurred within seconds following IJV compression. Intraocular Pressure(IOP) Measurement: IOP measurements were taken both before and afterapplication of the IN compression device, similar to ICP recordings. Thebaseline IOP was 11.18±2.27 mm Hg and was elevated to 16.27±3.20 mm Hgfollowing IJV compression (FIG. 9: p<0.01).

The increase of 31% seen in IOP following IJV compression is strikinglysimilar to that seen in ICP following IJV compression, both in magnitudeand rapidity of response (FIG. 10).

TBI—Impact Acceleration Model:

None of the animals died from the head trauma. Animals tolerated collarapplication without any observed untoward effects for the duration ofthe experiment. Specifically, there were no outward or visible signs ofdiscomfort, intolerance, or respiratory difficulty. All recoveredwithout complication and exhibited normal behavioral and feeding habitsup until the day of sacrifice. At necropsy, the brains were grosslynormal in appearance.

Stereologic Analysis of APP Positive Axons:

To determine the density of injured axons in the corticospinal tractsand medial lemnisci, the stereo logical optical fractionator method wasused. Compared to the normal anatomy found in previous experiments withsham animals, control animals without the collar demonstrated focallabeling of APP within many swollen contiguous and terminal axonsegments, consistent with impaired axoplasmic transport in traumaticaxonal injury. Following microscopic digital image acquisition frommultiple areas within the corticospinal tract and medial lenmisci frommultiple tissue slices, counting of APP positive axons in animals whoreceived the IJV compression collar demonstrated much fewer APP positiveaxons, at a frequency much more similar to sham animals, compared tothose undergoing injury without IJV compression (FIGS. 4A and 4B). Theseabnormal axons demonstrated typical morphological characteristics oftraumatic injury, primarily swelling and disconnection. By qualitativeanalysis, the experimental group showed (m±sd) 13,540±9808 vs.77,474±25,325 (p<0.01) APP positive axons/mm³ in the control group (FIG.12).

Example 4

Two groups of 10 adult male Sprague-Dawley rats were subjected to animpact acceleration traumatic brain injury. Prior to the injury, theexperimental group had application of a 15 mm wide cervical collar,which had two compressive beads over the internal jugular veins (IJVs).The control group had the experimental injury only. Intracranialpressure (ICP) and intraocular pressure (IOP) were measured before andafter IJV compression to assess collar performance. All rats weresacrificed after a 7-day recovery period, and brainstem white mattertracts underwent fluorescent immunohistochemical processing and labelingof beta amyloid precursor protein (APP), a marker of axonal injury.Digital imaging and statistical analyses were used to determine if INcompression resulted in a diminished number of injured axons.

Example 5

All animals survived the experimental paradigm and there were no adversereactions noted following application of the collar. In the experimentalgroup, IJV compression resulted in an immediate and reversible elevationof ICP and IOP, by approximately 30%, demonstrating physiologic changessecondary to collar application. Most notably, quantitative analysisshowed 13,540 APP positive axons in the experimental group versus 77,474in the control group (p<0.0), a marked reduction of greater than 80%.

Using a standard acceleration-deceleration impact laboratory model ofmild TBI, a reduction of axonal injury following UV compression asindicated by immunohistochemical staining of APP was shown. IJVcompression reduces SLOSH-mediated brain injury by increasingintracranial blood volume and reducing the compliance and potential forbrain movement within the confines of the skull.

Example 6 Internal Versus External Brain Protection

Compression of the IJV for 3 min prior to head trauma led tophysiological alterations in intracranial compliance, as evidenced bymodest increases in ICP and IOP, while simultaneously and markedlyreducing the pathologic index of primary neuronal injury in thestandardized rat model of TBI. Reduction in brain volume compliancecould prevent the differential motions between the cranium and the brainthat lead to energy absorption and neuronal primary and secondaryinjuries. These pathological changes include axonal tearing that disruptaxoplasmic transport resulting in axonal swelling and activation of theapoptotic cascades, as evidenced in this model by a statisticallysignificant reduction in APP counts of injured axons.

In the animal model of the present disclosure, applying the collarincreased ICP and IOP by 30% and 31%, respectively. The effect ofcompression of jugular veins on ICP is clinically well known. TheQueckenstadt test is used to indicate the continuity of CSF between theskull and spinal cord. In this test, ICP is increased by compression ofthe INs while the CSF pressure is measured in the spine through a lumbarpuncture. Increases in ICP have also been shown to occur with placementof tight fitting neck stabilization collars that likely compress theIJVs. Compression of the INs, which can occur when wearing shirts withtight collars or neckties, has also been shown to increase IOP. Notably,only mild compressive pressure is required to partially occlude the IJVsas they are a low pressure system. As the inflow of cerebral arterialblood continues after partial cerebral venous outlet obstruction, theintracerebral and venous pressure increases until the jugular venousresistance is overcome or the blood drainage is redirected to othervenous channels. In either case there is a reduction in intracranialcompliance and a modest increase in ICP.

The immunohistochemical assay used in the studies of the presentdisclosure is specific for axonal damage and results in a reliable rangeof measured damaged neurons. In addition, the Marmarou model ofacceleration-deceleration injury is an accepted and well-studiedmethodology by which to quantify the extent of TBI. The reduction indamaged axons, as evidenced by a marked reduction in APP counts, in theexperimental group with the IJV compression device is highlystatistically significant (p<0.01). Additionally, the change in ICP wasmeasured after applying the collar in five rats. The results show thatevery study rat had a reduction in axonal injury greater than the 95%confidence interval of the control group.

In a further aspect of the present invention it has been found thatapplying compression to the internal jugular vein not only reduces therisk of TBI, but also the risk of damage to the inner ear (specificallyNoise Induced Hearing Loss or Blast Induced Hearing Loss), spinal cordand structures of the eye. With respect to the ear, reducing IJV outflowwill congest the cochlear vein and thereby take up the compliance of theinner ear or more particularly the fluid within the inner ear. Since theauditory hair cells react directly to the vibrations in the cochlearfluid they are particularly susceptible to SLOSH energy absorption.Increasing the pressure of the fluid within the inner ear reduces thecompressibility of the fluid within the inner ear structure so thatblast energy is transmitted mechanically through the inner ear ratherthan absorbed by it in the form of vibration of the fluid. It is notedthat increase the fluid pressure does not generally reduce transversevibrations of the cochlear duct so the transmission of blast energythrough the inner ear may still lead to perforation of the eardrum. Butin many cases ruptured ear drums will heal or can be repaired. On theother hand, SLOSH-related damage to the fine auditory hair cells doesnot heal and cannot be repaired.

With respect to the spinal cord, it has been found that applying the IJVpressure techniques described herein reduces the compliance of fluidalong the spinal axis and thus reduces the risk of blast-related spinalinjury. The spinal injury mode is similar to the inner ear damage modein that the spinal cord tracts may be regarded as the sensitivefilaments in a fluid environment. Fluid vibration due to SLOSH candamage and may even sever spinal cord tissue. Increasing the CSFpressure by compression of the IJV according to the procedure disclosedherein will significantly reduce the CSF vibration due to blast energy.Moreover, increasing the CSF pressure increase the axial load-bearingcapacity of the spinal column which can reduce the likelihood ofcollapse of the spinal column due to blast energy.

With respect to the structure of the eye, the injury mode is similar tothat of the inner ear and spine in that vibrations (inelasticcollisions) of the vitreous humor can lead to permanent damage to theinternal structure of the eye. As demonstrated by a woodpecker's pectinapparatus's increasing intraocular volume and pressure which protectsthe internal structure of the eye; using the compression band to applypressure to the IJV as disclosed herein the intra-ocular pressure can beincreased 36-60%. Safely and reversibly increasing CSF and therebyintra-ocular pressure using the compression band disclosed herein canprevent or at a minimum significantly reduce the vibration and energyabsorption of the vitreous humor within the eye, thereby reducing therisk of blast-related damage.

Finally, as discussed above, the concussive events leading to TBI, hasalso been found to be a leading cause of anosmia (loss or impairment ofolfactory function, i.e., sense of smell). Increasing intracranialpressure as described above can reduce the risk of TBI and theassociated impairment of olfactory function. In the case of Breecher orbomb-sniffing dogs the collar may be sized to fit the neck of the animaland the pressure adjusted to account for the greater thickness of theneck at the IJV over that of a human subject.

The foregoing description addresses blast-related traumatic injuries tothe intracranial cavity, such as TBI, and injuries to the inner ear,spinal cord and ocular structure. The compression devices disclosedherein may thus be worn by military personnel during battle and removedwhen not in combat. Although certainly less dramatic, certain sports canexpose the intracranial cavity to concussive forces that create the riskof these same traumatic injuries, most notably football. The compressioncollar disclosed herein would be worn by the sports participant in thefield of play as well as a multitude of industrial or other potentialTBI risky avocations or professions. The embodiments of the collardisclosed herein are relatively non-intrusive and the “break away”feature described above eliminates the risk of the collar beinginadvertently pulled.

What is claimed is:
 1. A system comprising: (a) a pair of devices,wherein each device has an appropriate size and shape to restrict bloodflow egressing from the head of a subject when the devices are placedagainst the neck of the subject; and (b) a shirt comprising an integralcollar, wherein the collar (i) comprises an elastic material, (ii) isadapted to receive the devices, and (iii) in combination with thedevices, is adapted to apply a compressive pressure of about 5 mm Hg toabout 70 mm Hg to a pair of neck veins when the collar is fitted to theneck of the subject.
 2. The system of claim 1, wherein the devices eachcomprise an inflatable bladder.
 3. The system of claim 2, wherein eachinflatable bladder further comprises a pressure release valve.
 4. Thesystem of claim 2, wherein each inflatable bladder further comprises apump.
 5. The system of claim 1, wherein the devices each comprise aprotuberance.
 6. The system of claim 5, wherein each of theprotuberances is defined by the outward bend point of a resilientarcuate band having a general C-, V- or U-shape.
 7. The system of claim5, wherein each of the protuberances comprises an inflatable bladder. 8.The system of claim 7, wherein each inflatable bladder further comprisesa pressure release valve.
 9. The system of claim 7, wherein eachinflatable bladder further comprises a pump.
 10. The system of claim 1,wherein each of the devices is a rigid or semi-rigid plastic body. 11.The system of claim 1, wherein the neck veins include an internaljugular vein or an external jugular vein.
 12. The system of claim 1,wherein the compressive pressure is about 5 mm Hg to about 25 mm Hg. 13.The system of claim 1, wherein each of said devices further comprises anadhesive.
 14. The system of claim 1, wherein the devices are integral tothe collar.
 15. The system of claim 1, wherein the devices are removablefrom the collar.
 16. The system of claim 1, wherein the devices areattached by a resilient arcuate band sized to encircle a portion of theneck of the subject.
 17. The system of claim 16, wherein the resilientarcuate band is designed to encircle the neck of the subject except forthe area substantially defined by the laryngeal prominence.
 18. Thesystem of claim 16, wherein the resilient arcuate band comprises asemi-rigid shape-memory material.
 19. The system of claim 16, whereineach of the devices define a thickened region of resilient arcuate band.20. The system of claim 19, wherein each of the devices is a rigid orsemi-rigid plastic body.